It has previously been proposed--see, for example, the text "Techniken, Systeme, Maschinen" ("Technology, Systems, Machines"), by Oscar Frey, published by Polygraph-Verlag, 1979, pages 49 et seq.--to pull a plurality of printed paper webs, stacked above each other, over a folding former or folding triangle or funnel, to form a longitudinal fold therein. The web or webs are folded in one pass. The folding force is derived directly from the pulled web. The geometry of the folding former or similar structure causes the path of the web to change by about 90.degree.. If a plurality of webs are superimposed above each other, differences in path length may occur so that reliable pull-off cannot always be ensured.